Prime Minister John Key says the Maori Council is free to confront him about water rights during talks at Waitangi, but won't back down on the Government's stated position.
The council and a group of Waikato Maori trusts have appealed against a High Court ruling that there is no connection between the Government's proposed sale of shares in state-owned enterprises such as Mighty River Power and Maori claims to water.
The case was heard by the Supreme Court last week and a decision is expected in about two weeks.
Waitangi marae trustees have asked council co-chairman Maanu Paul to open the forum at Waitangi in the Bay of Islands on Tuesday.
The council says the Government is picking pet Maori to discuss water rights with and Mr Paul plans to force Mr Key into a discussion.
Mr Paul said he would use the opportunity to tell Mr Key that the Government can't dodge the issue of water ownership forever and, under the Treaty of Waitangi, Maori should be partners with the Crown in any policy development for water.
The Government has refused to speak to the council about plans to partially privatise the state-owned power companies, and instead is dealing directly with iwi affected by the sales. However, Mr Paul said the Government has a legal obligation to discuss water rights with his organisation as well.
"What they're doing is picking pet Maori to talk to. That's not what the jurisprudence says they have to do. And so, they speak with forked tongue and on the basis of that, they are denying the right of Maori to act in their role as the Treaty partner."
The Prime Minister said he is happy to defend the Government's stance on water ownership and its treatment of Maori generally.
"This is a government that has completed a huge number of settlements in the time that we've been in office.
"We've been working very hard in the areas where we see under-achievement occurring and where it's having a big impact on Maori - particularly around education. Think about Whanau Ora - a good example of a programme which we think will at least help at-risk Maori families."
John Key said he understands the Maori Council's perspective on water rights, but stands by the Government's stated position that, under common law no-one owns the water, but it does recognise Maori rights and interests.
But the council says its legal fight over water rights is not a battle to win total ownership. Co-chairman Sir Eddie Durie said the simplistic statement that you can't own water misses the point and the council's argument.
"A proprietary interest is, for example, not the right to own the water, but to own the right to utilise a water resource for a particular purpose."
Sir Eddie said all people should have the right to free access to water for domestic purposes as it is a basic human right.
Meanwhile, Maori leaders plan to deliberate a number of other issues, including the social policy Whanau Ora, housing and education on Tuesday.
Freshwater Iwi Leaders Group member Tom Roa says they want to maintain the impetus gained last year with the Crown and make sure that customary rights and the rights of all New Zealanders are protected. Mr Roa said it is important for iwi that their traditional rights and interests are recognised by central and local government.
Maori Party supports council
Maori Party co-leader Pita Sharples says his party is supporting the Maori Council's push to secure water rights.
Dr Sharples told Radio New Zealand's Morning Report programme on Tuesday there should be no doubts about his party's support for the council.
"We're part of the Government and the coalition, I know, ... but we're also here on behalf of Maori and the Government knows this and that's why we are part of the Iwi Leaders Groups that meet with Government. Every time I sit in as Minister of Maori Affairs, they know full well that I'm there for that portfolio."
Dr Sharples said he expected a warm welcome for his party as it goes onto the marae.
Council given good hearing - lawyer
A lawyer representing the Maori Council in its legal challenge over water rights says the council's case has been given a good hearing by the Supreme Court.
Speaking from Waitangi, Donna Hall told Radio New Zealand's Morning Report programme on Tuesday she worried with the fairly firm position taken very early by the High Court, but the Supreme Court has been different.
"There are certain advantages, of course, that the Supreme Court's got which a judge sitting alone in a High Court never has - that is, the judge is sitting alone.
"Here, you're dealing with a bench of five ... of the finest judicial minds in the South Pacific. So it's always easier to make these hard decisions when there's a few of you. You can throw the ideas around."
Ms Hall says there will not be a decision until at least 18 February.